Boosting the thermal stability of emulsion–templated polymers via sulfonation: an efficient synthetic route to hierarchically porous carbon foams
2016 (English)In: ChemistrySelect, ISSN 2365-6549, Vol. 1, no 4, 784-792 p.Article in journal (Refereed) PublishedText
Hierarchically porous carbon foams with specific surface areas exceeding 600 m2 g−1 can be derived from polystyrene foams that are synthesized via water-in-oil emulsion templating. However, most styrene-based polymers lack strong crosslinks and are degraded to volatile products when heated above 400 oC. A common strategy employed to avert depolymerization is to introduce potential crosslinking sites such as sulfonic acids by sulfonating the polymers. This article unravels the thermal and chemical processes leading up to the conversion of sulfonated high internal phase emulsion polystyrenes (polyHIPEs) to sulfur containing carbon foams. During pyrolysis, the sulfonic acid groups (-SO3H) are transformed to sulfone (-C-SO2-C-) and then to thioether (-C−S-C-) crosslinks. These chemical transformations have been monitored using spectroscopic techniques: in situ IR, Raman, X-ray photoelectron and X-ray absorption near edge structure spectroscopy. Based on thermal analyses, the formation of thioether links is associated with increased thermal stability and thus a substantial decrease in volatilization of the polymers.
Place, publisher, year, edition, pages
2016. Vol. 1, no 4, 784-792 p.
Emulsion-templated polymer, sulfonation, pyrolysis, spectroscopy, carbon foam
Research subject Chemistry with specialization in Materials Chemistry
IdentifiersURN: urn:nbn:se:uu:diva-283174DOI: 10.1002/slct.201600139OAI: oai:DiVA.org:uu-283174DiVA: diva2:918694